Bomb slip, towing gear, and analogous releasable attachment



April 10, 1951 R. K. PIERSON ETAL I 2,543,053

BOMB SLIP, TOWING GEAR, AND ANALOGOUS RELEASABLE ATTACHMENT Filed July 5 1947 2 Shets-Shet 1 INVNTOR 51. 03%, M, M v wM April 10, 1951 R. K. PIERSON EIAL.

. BOMB SLIP, TOWING GEAR, AND ANALOGOUS RELEASABLE ATTACHMENT 2 Sheets-Sheet 2 Filed July g9, 1947 INVQ VT' R' Patented Apr. 10, 1951 U N i TEX ATENT BOMB SLIP, TOWING GEAR, AND ANALO- GOUS RELEASABLE ATTACHMENT Application July 30, 1947, Serial No. 764,800 In Great Britain October 20, 1942 Section 1, Public Law 690, August 8, 1946 Patent expires October 20, 1962 '7 Claims.

' l The invention has reference to releasable attachments for use in conjunction with objects such as bombs, mailbags, supply containers or .other articles to be dropped from aircraft, or for .use in towing operations, and in other analogous circumstances, such attachments being of the type wherein the load-engaging members (e. g. hooks) are released through the medium of a toggle mechanism by an elecuro-magnetically operated tripping device'which, when actuated, imparts a lateral blow to the togglesufiicient to collapse the latter and initiate-or effect the releasing operation. The object of this invention is to provide an improved construction of tripping mechanism for a releasable attachment of the type re-.

ferred to.

Ina releasable attachment of said type, the tripping mechanism provided by the present invention comprises a rotary armature carrying a projecting abutment which, when the armature.

rotates on being energised, impinges upon and imparts a lateral blow to the braced portion of the toggle mechanism, and means for arresting the rotation of the armature when the toggle mechanism has moved to the collapsed position. The tripping device may be applied to a releasable attachment wherein a pair of load-engaging jaws are held engaged by the presence of a movable 1' stop between opposed bearing faces or cooperat- "ing parts of said jaws, and in which the arrangement is suchthat the. load itself normally reacts to impose forces tending to disengage the jaws and to eject said stop; in such case the toggle mechanism is arranged normally to impose a restraining force on said stop in a direction opposed to said ejective'force and, when released, to withdraw or allow theejection of the stop on collapsing.

One embodiment of the invention is hereinafter described by way of example with reference to the r accompanying drawings, which illustrate the application of atripping mechanism as characterised by'this invention to an attachment suitable for use with bombs and other articles to be P dropped from aircraft in flight; In said draw- 'ings Figs. 1, 2; 3 and 4 are elevations of the at- -tachznent (Fig. 2 being a fragmentary View) as seen-when one-half: of the enclosing casing is removed. and they'illustrate respectively the relative positions of the component parts (a) when F r supporting a load; (1)) immediately after the trip- -.--ping mechanism has been operated, when the "load is completely freed, and (11) when the jaws have automatically resumed their operative posi- *tions ready for themechani'sm to be re-set. Fig.

link 58 is pivotally anchored at 69.

5 is an end view ofthe attachment as shown in Fig. 1, with both halves of the casing assembled, and Fig. 6 is a fragmentary detail illustrating a cross-section, taken on the line VIVI of Fig. 2, of the rotary armature hereinafter described.

It will be seen from the drawings that the attachment comprises a slip, constructed of two complementary recessed parts 59, 60, which when assembled enclose cavities in which the moving parts are contained, said slip being apertured at 6| for connection to a hoisting device of known kind and having two load-engaging jaws 62, 63 mounted upon a common pivot 64. The jaws 52,

. t3 have pincer-like-extensions with opposed plane bearing faces 62 I, 63! arranged so that the presence of a stop 66 of roller form between such faces retains said jaws. in the closed position; said faces B21, 63! are inclined to each other when in the position shown in Fig. 1 and the angle included between them. is adjusted in accordance with the friction angles of the material so as to produce a resultant force which tends to eject the stop 66 from between said faces, the operative force being derived from the load which is suspended from a shackle. resting upon the tips of the jaws 62, 53 and which tends to force the jaw-tips apart.

The locking mechanism for holding the roller 6% between the jaw-faces 6.2!, .63! incorporates the toggles 67,68 and 10, 1|. The link 61 of the primary toggle carries said roller. 66, whilst the To the central pivot of the toggle 61, 68 is connected the link ll] of the second toggle, which link In is pivoted at its opposite extremity to the free end of a bifurcated lever ll pivoted upon the spindle 12 of a rotary armature 73, which constitutes the electromagnetically operated striker provided by the invention.

Said armature i3 is almost completely enclosed in a cylindrical cavity it formed by the halves 59, $0 of the slip, inthewalls of which cavity are inset softiron cores '75 extending substantially through the two halves 59, 60. The armature comprises windings, indicated conventionally at 55in Fig. 6, and pole-pieces 80, 8|, 82, and 83. Said windings-l5 are connected to contacts in the circumferential face of an insulated block 11 which, as the armature 13 rotates between the positions shown in Figs. 1 and 2, cooperate with spring-pressed contact members 18 which are in turn connected to the fixed contacts 19 (Fig. 5). These contacts 19 make connection with corresponding spring-pressed contacts in the inner wall of a housing (not shown) into which the of the slidable spring-pressed plunger 85.

3 slip 59, 653 is arranged to be inserted when hoisted into position upon the aircraft. The windings 16 of the armature 13 are mounted upon a spiderlike member of which the spokes are constituted by the pole-pieces 80, 8|, 82 and 83. The polepieces carry outwardly projecting lugs 8M, 8| I, f

82! and 83! respectively. Thelugs Bill and 83! lie on opposite sides of the bifurcated lever H.

When the mechanism occupies the position depicted in Fig. 1, with a load supported by the jaws 62, 63, the toggle-members 61, 68 are almost in alignment, so that a great proportion of the force tending to eject the roller 66 from between the surfaces 62 l 63 l is resisted by the anchorage 69. The remainder of such ejective force tends to displace the link 10 longitudinally towards the left, as viewed in Fig. 1, and this in turn is'resisted by the bearing 12 of the armature 13 since the said link 10 and the pivoted lever H are braced substantially in alignment.

To break the toggle for the purpose of releasing the jaws 62, 63, the armature current is switched on. The pole-pieces are attracted towards the soft iron cores .15 in an anti-clockwise direction and the consequent rotation of the armature 73 causes the lugs Bill of the pole-pieces 80, lying immediatelybeneath the lever 1!, to impinge against the portions II I of said lever 1! with an impetus amply sufiicient to collapse both toggles and permit the ejective force due to the load on the jaws 62, 63, to expel the roller 53, permitting said jaws 62, 63 to open and so release the bomb shackle 65, as shown in Fig. 3. In order that the armature 13 when actuated may acquire added impetus it is convenient to allow a certain degree of clearance, indicated at 86, between the edges of the lever H and the lugs 80!,83! of the adjacent pole-pieces 8i] and 83. Helical springs 88 (Fig. 6) having their respective extremities attached to the armature 13 and the non-rotatable spindle 12 are provided for the purpose of constantly urging the armature l3 clockwise (as viewed in Fig. 1). This has the efiect, when the armature is not energised, of causing the lugs 83l of the pole-piece 83 to con tact the portions "I of the lever H and thereby to hold the latter against an abutment 15!, the position of which is carefully adjusted to produce substantial alignment of the toggle Hi, II.

On operation of the armature to disengage the jaws, the magnetic attraction between the polepieces and the soft iron cores has the effect of imparting a braking action on the further rotation of the armature as soon as it has assed the position in which the pole-pieces are nearest to the soft iron cores. The impetus of the ejected stop-roller 66 and the toggle-parts associated therewith however is sufficient to carry the armature 13 round to the position shown in Fig. 2, forcing the insulated contact-block i1 past the bulges of the spring contacts 18, so that the armature is stopped and is held in this position with its operating circuits interrupted. In operation, after the shackle 65 has passed the tips of the jaws 62, 6 3, the latter are returned to their initial positions by springs 81, 8'1, and the parts then assume the position illustrated in Fig. 4. To re-set the toggles, the armature is given an impetus in the clockwise direction, suf

ficient to force the block I! past the bulges of the contacts 18, by a sharp push upon the head 85! The inclined face of thetip of said plunger coacts with the side of the pole-piece 83 so that when depressed the plunger pushes said pole-mece 83,

sideways and rotates the armature 13, which is by this means and with the assistance of the springs 88 returned to its initial position. The jaws 62, 53 being closed and the space between the surfaces 52!, E3l being fully open, the roller 56 is caused by gravity and by said springs 88 acting through the armature 13 upon the toggle 10, ll

to resume its position between such surfaces, carrying the toggle linkage 6?, 68 and it, I! with it until they likewise have taken up again the position depicted in Fig. l. The springs 88 also serve to prevent the toggle '18, H from bouncing out of the aligned position under jolting or vibration of the aircraft.

If for any reason it is desired to release the toggle mechanism mechanically, this can be effected by a downward push upon the head of the plunger 85. The operative part of the plunger being of wedge-formation, its movement presses a pivoted stop-member 84 laterally from the position shown in Fig. l and this motion is communicated to the pole-piece 82 of the armature l3, rotating the. armature and breaking the toggle 10, H as hereinbefore explained. The

, thickness of the tipof the member 84 must be such that the rest positions of the armature l3 and of the toggle arts 10, H are solely determined by the contact of the lever H against the abutment 15I.

What we claim as our invention and desire to secure by Letters Patent is:

l. A tripping mechanism for a releasable attachment of the type referred to, comprising a toggle mechanism, a rotary armature carrying a projecting abutment which, when the armature rotates, impinges upon and imparts a lateral blow to the toggle mechanism, electro-magnetic means for rotating the armature, and means for arresting the rotation of the armature when the toggle mechanism has moved to the collapsed position.

2. In tripping mechanism as claimed in claim 1, the arrangement wherein two projections carried by the armature are located one at either side of a movable link in thetoggle mechanism so that when the armature revolves in one direction one of said projections impinges on said link to impel it towards the collapsed position of the toggle mechanism, whilst on a reverse movement of the armature the second projection returns said link to the .braced position of the toggle.

3. The mechanism claimed in claim 2, wherein a certain degree of lost motion is permitted between the armature projections and the movable toggle-link.

4. A tripping mechanism as claimed in claim 1, wherein the armature is subjected to a magnetic braking action after it has effected the collapse'of the toggle.

5. The mechanism claimed in claim 1, wherein the electrical connections to the armature are eifected through the medium of stationary con-- I prising a spring-pressed plunger of which the exrtremity is arranged when said plunger is manually depressed to impinge upon an abutment carried by the armature and thereby to rotate Number the same towards its initial pos1t1on. 695,724 7. In tripping mechanism as claimed in claim 1,765 397 l, supplementary manual means for operating 5 the armature to collapse the toggles.

' REGINALD KIRSHAW PIERSON. Number REGINALD ARTHUR FIRMAN. 79,538 62,573 REFERENCES CITED m 510 175 The following references are of record in the file of this patent:

. 6 UNITED STATES PATENTS Name Date Herman Mar. 18, 1902 Alkan et al. June 24, 1930 FOREIGN PATENTS Country Date Austria Dec. 29, 1919 Norway Dec. 7, 1938 Great Britain July 28, 1939 

